About one week ago, I noticed the dark red-purple circular marks on my back. Today I noticed two more have popped up. They are more or less in a line across my back. They are not raised and do not hurt at all. I am a healthy 23 year old female. The past 4 weeks I've started eating a healthier diet and a weightlifting work out routine. Other than that, there has been little changes to my lifestyle.
Here is a photo of the marks: http://tinypic.com/r/22135f/9